Method of freezing food



Oct. 5, 1948. F. B. DOYLE 2,450,545

METHOD OF FREEZING FOOD original Filed oct. 28,- 1943 t 2 sheets-sheet 1 4a 8 zaad g1 8 305s HIS ATTORNEY- Oct. 5, 1948. I F. B, DOYLE l 2,450,645

METHOD OF FREEZING FOOD Original Filed Oct. 28, 1943 2 Sheets-Sheet 2 l NV ENTOR Franlpoyl.

HIS ATTORNEY.

Patented Oct. 5,- 1948v METHOD F FREEZING FOOD Frank B. Doyle, Phllliplburg. N. J., assignor to Ingersoll-Rand Company, New York. N. Y., a corporation of New Jersey original application october 2s, 194s, vsmul No.

Divided and this application November 15, 1944, sensi No. 563,595

s claims. (ci. iis-19a) 'Ihis invention relates to the processing of food products, and more particularly to apparatus for and method of freezing'vegetable material and the like.

This is a division of my co-pending application Serial No. 507,993, filed October 28, 1943, now Patent No. 2,407,482,

It is an object of the invention to avoid the exposure of the material to air throughout all the steps of processing and during the transference of the material from one processing zone to another.

A further object is to preserve the original vitamin content of the food product.

Another object is to facilitate the transfer of the food product from one processing zone to i another.

Still another object is to avoid the unnecessary expenditure of power for processing the material.

Other objects will be in part 'obvious and inV part pointed out hereinafter.

In the drawings accompanying this specifica-` tion' and in which similar reference numerals refer to similar parts, l

Figure 1 is an elevation, shown diagrammatically, of apparatus constructed in accordance with the practice of the invention,

Figure 2 is an elevation, partly broken away, of the upper part of the main processing unit,

Figure 3 is a similar view showing the remaining lower portion of the main lprocessing unit,

Figure 4 is a transverse view taken through Figure 2 on the line 4-4 looking in the direction indicated by the arrows,

Figure 5 is a similar view also taken through 'Figure 2 onthe line 5 5, and

Figure 6 is an elevation, partly broken away and somewhat enlarged. of a detail.

Referring more particularly to the drawings,

the apparatus. designated in its entirety by 20, comprises a main processing unit 2i and evacuating means. designated broadly 22, for creating a vacuum in certain zones of the main unit 2i to freeze the material intended to be processed.

In a preferred form the main unit 2i comprises an. elongated casing 23 that may be constructed, as shown, in sections of suitable length and occupies a vertical position so that the food material may pass therethrough by gravity.

The interior ofthe casing 23 is divided into blanching, freezing and storing chambers 24, 25 and 26, respectively, the blanching chamber 24 being at the upper -end of the casing and separated from the freezing chamber 2li by a. wail 21. At the upper end of the blanching chamber is a charging opening 28 to admit the food material into the blanching chamber, and fthe end portion of the casing' dening the openingv constitutes a seat 29 for a cover 80 forming a. closure for the opening 28. A sealing member 3i in the cover I0 engages the seating surface 28 to seal the casing at this point.

The cover lll is manipulated through the medium of a lever $2 having an end'33 pivotally connected to a lug 34, on the casing,u by a pin 35 extending through the two. The lever 32 overlies the cover 30 in spaced relation thereto, and in its opposite end is a slot 38 to receive an eyebolt 31, the eye 38 of which is pivotally connected to a lug 39 on the casing 23. 1 The force required for holding the cover in the closed position may be applied by a nut 40 on the eye-bolt and seating against the lever 32.

As will be explained more fully hereinafter.l

the vegetable material is subjectedsuccessively to a blanching medium and to a vacuum in the chamber 24. It is, therefore, desirable that provision be made to enable the `vacuum'in the cham-f` ber 24 to be conveniently broken preparatory to lifting of the cover 30. To this end an atmospheric port 4I is formed in the cover and the lever 32 carries a sealing member 42 to overlie the outer end of the port 4i. In order, therefore, that the sealing member 42 may be' removed from its sealing position before force is applied to the cover for lifting it, the latter is connected to the lever in such wise as to permit of relative movement between the two. This may. as shown, be accomplished by means of bolts 43 that extend loosely through the lever and are threaded into the outer surface of the cover. The bolts are of such length that when the cover is in the closed position the heads of the bolts are out of engagement with the lever which may, therefore, be moved independently of the cover 30 for first lifting the seal ing member. and the lever nextlengages the bei;

heads for removing the cover from the casing.

,In the arrangement shown, `the pressure of the lever 22 is transmitted to the cover 30 by the sealing member 42, and the sealing member is imbedded in a container 44 that is pivotally connected to the lever 32 to enable the sealing member to readily assume a correct position lwith respect to the port 4i.`

After being processed in the blanching chamber 24 the material is dumped into the freezing chamber through a transfer opening 45 in the wall 21. The opening 45 is beveled to guide the material toward -the central portion of the freezing chamber 2l and forms a continuation of. the

acude-is inner surface of a hopper 48 having its lower end 41 seated in the wall 21. The hopper may be constructed of meshy material or be provided withsuitable perforations 48 to permit the free flow of fluid medium to and from the material held by the hopper.

The opening 45 is controlled by a valve 48 the lower portion of which is beveled to conform with the opening 45 and carries a sealing member 50 to engage the surface of the opening 45 for eiecting a seal between the chambers 24 and 25. vThe valve 48 is of frusta-conical shape and is pivotally connected to an end of an arm I the opposite end of which may be nxedly connected, in any well known manner, to a horizontal shaft 52 journaled in the casing 23. One end of the shaft 52 projects from the side of the casing to the exterior thereof and carries a lever 53 whereby the valve may be manually lifted and lowered with respect to the opening 45. Suitable sealing material 54 is inserted in the casing 23 'around the shaft 52 to prevent leakage between it and the casing.

The freezingchamber 25 may, as shown, be of somewhat larger diameter than the chamber 24 and contains a cylindrical basket 55 of meshy material and of smaller diameter than the chamber to provide an annular space 58 between the basket and the casing. The basket rests with its lower end upon a wall 51 separating the freezing chamber 25 from the storage chamber 28 and its upper end lies directly beneath the transfer opening 45 to receive the vegetable material and extends into a ring 58 lying in an annular recess 58 in the casing 23 to assist in holding the basket coaxial with the casing.

Means are provided for preventing partly processed material from being deposited upon frozen material in the lower portion of the freezing chamber. To this end plates or bailles, two in the example shown and designated 6D and 8l. are arranged within thebasket 55. The baffles are tiltable and carry trunnions 62 that are journaled in support bars 83 on the exterior of the basket. The support bars may be secured to the basket in any suitable manner, as by spot welding, and may be additionally supported by the ring 58.

The bafiles are preferably of elliptical shape to provide points or portions E4 of maximum dis-l tance from the axes of rotation of the baiiles to engage the basket at points above and below the transverse planes of the trunnions and thereby cause the bailles to always assume inclined positions for intercepting the material. This is desirable for the reason that the major portion of the loads of material will then rest upon the low sides of the baflles and only a light force will be required for tilting them.

In the arrangement shown, the bailies 68 and 8i tilt in unison, although in opposite directions,A

and responsively to the movements of the valve 48. They are accordingly connected by a rod 65 that is adjustable for length and is pivotally connected at one end to a lug 86 on the high wing of the baille 8i and at its opposite end to a lug 61 on the low wing of the bailie 80. The rod 85 thus extends diagonally of the chamber 25 and causes the corresponding ends of the baffles to move simultaneously in opposite directions whenever tilting force is applied to one of the battles.

In the present instance this force is applied, in part, manually through the lever 53 and associated elements including the valve 49 and a rod 88 on the valve that extends downwardly into the basket 55. The rod is guided at a suitable disbailles.

A tension spring 15, also in the basket 55, is connected to the opposite end of the bar 13 and to the annular plate 10 and presses the bar` 13 against the pointed end 12 of the rod 88 to cause the bar 13 to follow the movement of the rod. These movements of the bar 13 are transmitted to the baille 88 by a rod 18 similar to the rod 85 and pivotally connected at its upper endto the bar 13 between the rod 88 and the spring 15. The opposite end of the rod 18 is pivotally connected to the low Wing of the baille 80.

The portion of the freezing chamber below the vbaille 8i may be of a capacity capable of accommodating a desired number of batches of frozen vegetablematerial, and at its lowermost end is a hopper 11 shown as an integral part of the wall 51 and extending into the storage chamber 28 to guide the frozen product thereinto. The discharge opening 18 of the hopper is normally sealed by a device I8 similar in all essential respects to that used for sealing the charging end of thc blanching chamber 24 and accordingly including a cover 18 containing a sealing member 8|) to engage the end of the hopper 11.

In this arrangement the cover 19 lies above the operating lever 8| to which it is interlockingly connected by the bolts 43, and the bolts, as will be understood, have the required degree of sliding movement in the leverV 8| to permit the lever to move relatively to the cover 19 for first unseating the sealing member 42 to break the vacuum in the freezing chamber. The lever 8i is moved by manual force applied to an arm 82 located exteriorly of the casing 23 and affixed, in a suitable manner, to a rocker shaft 83 for the lever Bl.

The storage chamber 28 is preferably of the same capacity as the lower or storage portion of the freezing chamber and has a hopper 84 at its lower end through which the material passes into a guide member 85 partly encircling the hopper 84 to guide the frozen material into a suitable receptacle for transportation or nal storage. The discharge end 88 of the hopper is normally sealed by a sealing device I8 constructed in all respects and operated in the same manner-as the sealing device i8.

As has been hereinbefore stated, the material introduced into the blanching chamber for the first step of processing is subjected successively to a blanching medium such as steam and to a Communication between the blanching chamber 24 and the condenser is controlled by a manually operable valve 93 in the conduit 90, and an outlet is provided for the escape of air from the blanching chamber to the atmosphere by a conduit 84 communicating with the conduit 80 at a point between the valve 93 and the blanching assaut* chamber 24. The outlet end of the conduit 94 is controlled by a check valve 95 that serves to prevent the i'iow of air from the atmosphere through the conduit to the blanching chamber, and in an intermediate portion of the conduit 94, between the check valve 99 and the conduit 90 is a thermostatic trap 99, of a well known type, including a casing 91 to which the adjacent ends of the conduit 94 are connected. The valve element 99 is actuated by a thermostat 99 for controlling communication between the several sections cf the conduit 94 attached to the casing 91.l

The means employed for creating the desired' 6 ing the baule 90 to tilt into and the baille 9| to tilt out of engagement with the basket.

The material will then lodge upon the bame 90, and upon the subsequent lowering loi the valve 49 to its sealing position its movement is transmitted through the rod 99 and associated linkage to the baflles for rocking them simultaneously to their oth'er limiting positions. During this movement of the baiiies the material is'dumped from vacuum in the freezing chamber 29 comprises a pair of steam jet ejectors |00 and |0| arranged in'tandem between the freezing chamber and the condenser 9|. The ejector |0I may, as shown, be arranged to discharge directly into the con-l denser 9| at a point below theconduit 90 and the ejector |00 communicates with thefreezing chamber 29 at a point near the upper end thereof through a conduit |02. Another stage of Apumping in the evacuating means 22 is effected by a steam iet ejector |09 connected to the upper end of the condenser 9|.

The operation of the device is as follows: Let it be assumed that all the jet ejectors are in operation for evacuating the freezing chamber 29 and the condenser 9| and that it be intended to charge the blanching chamber 24 with material for the initial step of processing it. Under these conditions the valve 49 rests upon the beveled surface of the transfer opening 49 to seal the upper end of the freezing chamber,A and the outlet ends of the hoppers 11 and 94 are sealed by the devices i9 and I9. The valve 93 then also occupies its closed position to prevent communication between the blanching chamber and the evacuating means.

After the vegetable material has been placed in the blanching chamber 24'the cover 39 is placed upon the seating surface 29 and the sealing member over the port 4i and both are clamped in seallng position by means of the nut 40. Steam is then introduced into the blanching chamber through the pipe 91 for blanching the material. The steam thus admitted into the chamber 24 drives the air therefrom through the outlet open@ ing 99, the conduit 94 to the atmosphere. and when the steam reaches the thermostat 99 the latter will move the valve 98 into position to cutoff communication between the blanching chamber and the atmosphere. The chamber 24 will then be completely sealed and steam of the required pressure. as for example eight pounds gauge. will be permitted to flow into the blanching chamber for a suitable period of time. say two or three minutes. to effect inactivationl of the enzymes contained in the food product.

At the expiration of the blanching period the time of which, as will be readily understood, may vary with the pressure of the steam and the product being treated, the flow of steam' into the blanching chamber 24 is cut-off. Immediately thereafter the valve 99 is opened to place the blanching chamber 24 in communication with the condenser 9| and thereby subject the material to the condenser pressure which is preferably maintained at about one and one-half inches of mercury, absolute.

the baille 90 upon the baille 9| where it will remain as'long as the valve 49 occupies its sealing position and will be subiected to the higher vacuum in the freezing chamber to -an absolute pressure required to -effect complete freezing thereof. p

Meanwhile, the chamber 24 is again charged with material. it being understood, of course, that during this timethe valve 99 is flrstclosed to cutoil communication'between the blanching chamber and the evacuating means 22. After the new batch of material has been blanched and the chamber 24 again evacuated the valve 49 is raised to dump the material into the freezing chamber.

The spring 19 will then tilt the bailles 90 and 9| to bring the baille 90 into position for intercepting 4 the material dropping from the chamber 24 and After the blanching chamber 24 has been evacv to dump the previous batch from the baille 9| into the lower portion of the freezing chamber. This sequence of events may be repeated until the stor age space below the baffle 9| has been filled.`

Whenever it is intended to remove the frozen product from the freezing chamber and'assuming, of course, that the sealing device i9 occupies its sealing position on the end of the hopper 94,

- the sealing device I9 is removed from the end of the hopper 11. The frozen product will then fall into the storage chamber 29, whence it may be removed for final storage.

After theproduct has been thus transferred to the storage chamber 29 the sealingdevice |9 is again placed in its sealing position and the processing steps heretofore described may be repeated in the chambers 24 and 29 for treating other batches of material. l

f From the foregoing description it will be readily appreciated that the vacuum in the freezing chamber need be broken vonly at widely spaced intervals of time. For example, in a unit having a storage space in the freezing chamber capable of accommodating six batches of material and assuming that the 'time required for blanching, freezing and transferring the material thereto is approximately five minutes per batch, the vacuum in the freezing chamber need be broken only at intervals of thirty minutes, or thereabouts. This is a highly desirable feature since it obviates the frequent exposure of the product to air which,

as is well known, has a deleterious effect upon the v processed material to reach the storage space in the freezing chamber and be transferred into the storage chamber 29 in that condition.

I claim:

1. The method of processing food in two zones which comprises subjecting the food to a blanching medium in one zone, utilizing such blanching aime medium for expelling sir from said one zone, next subjecting the food in said one zone to s. vacuum, maintaining a vacuum in the other zone, interconnecting the zones, transferring the ,food to said other zone, cutting-oil' communication between the zones, and continuing subjecting the ioodio a vacuum for freezing the food.

2. The method of processing food in two zones which comprises subjecting the food to a blanching medium in one zone, utilizing such blanching medium for expelling air from said one zone, next subjecting the food in said one zone to a vacuum. maintaining such vacuum, maintaining a. vacuum in the other zone, establish direct communica.- tion between the zones and simultaneously transfer the food to the said other zone, cutting-of! communication between the zones, and continuing subjecting the food to a vacuum for freezing the food.

3. The method of processing food in two zones which comprises subjecting the food to avblanch- REFERENCES errno The following references are o! record in the tile of this patent:

UNITED STATES PATENTS Number Name Date 1,884,429 Warner Oct. 25, 1932 1,910,009 Grayson May 23, 1933 1,938,522 Grayson Dec. 5, 1933 Bensel Dec. 5, 1944 

